NON-AQUEOUS CHEMISTRY OF URANIUM PENTAFLUORIDE

Following a report that uranium pentafluoride forms stable solutions in acetonitrile, we have investigated the remarkable behavior of β-UF5 in a wide variety of coordinating and noncoordinating nonaqueous solvents. Nitriles, dimethyl sulfoxide, and dimethylformamide dissolve up to 0.3 g of UF5/mL at 25 °C to form stable U(V) solutions containing UF6- anions and solvated UF4+ cations. Salts of the type [UF4Lx] [UF6] have been isolated from these solutions. Alcohols appear to form metastable solutions of U(V) from which mixed alkoxide-fluorides precipitate. Hydrocarbons, ethers, ketones, and amines are chemically attacked by β-UF5, whereas fluorocarbons, SO2, and CS2 fail to react. A convenient method is also given for producing UF6- salts with a variety of cations. Solutions and isolated solids were characterized by elemental analysis and electronic, infrared, Raman, and EPR spectra. © 1979, American Chemical Society. All rights reserved.